This invention relates to a recording disc, and more particularly, to an improved center core structure for a flexible recording disc and a related method of manufacture.
Flexible recording discs have gained widespread use due to the ever increasing popularity of word processors and personal computers. An example of a currently used, popular, flexible, recording disc in a cassette is described in Sony Corporation's U.S. Pat. No. 4,445,155, which is shown in FIG. 1 herein.
More particularly, the cassette is indicated generally by reference numeral 10. A flexible recording disc 12 is housed therein. The disc 12 is made of a thin, polymeric film base, such as MYLAR.RTM., with a magnetic layer formed on at least one side thereof. The disc 12 includes a substantially planar, circular, stamped, stainless steel center core 13 including a hub 14 surrounded by a flange 20. A portion of the core 13 extends through a circular aperture 18 formed centrally in the flexible recording disc 12 and the flange 20 is connected to the disc 12 by means of a double-sided adhesive member 16, known as an "A-ring". In addition, a generally square-shaped, motor shaft insertion aperture 22 and a rectangular, positioning pin insertion aperture 24 are formed substantially centrally of the center core 13. Further, the cassette 10 includes a cover 26, a base 28, fabric liners 30 and 32, and a flexible wiper spring 34.
Conventionally, assembly of the flexible recording disc 12 shown in FIG. 1 includes the following steps. The adhesive A-ring 16 is applied to the underside of the flange 20 of the pre-stamped, metal center core 13. Then, the center core 13 is positioned in the aperture 18 of the flexible recording disc 12 from above so that the flange 20 adheres to the disc 12 around the aperture 18 via the A-ring 16.
The above-described flexible recording disc and method of manufacture, as well as an improved method of manufacture, all using an adhesive "A-ring," are more fully described in Assignee's co-owned U.S. Pat. No. 4,613,392.
The conventional disc and the related method of manufacture are known to suffer several significant drawbacks from an automation and cost efficiency point of view. Namely, the dimensional requirements of the metal center core, especially flatness of the flange, are extremely critical and create a major production quality control problem. Further, creating a consistently high quality center core by stamping metal is difficult. Finally, handling the A-ring is very problematic due to its relatively small, circular size and its double-sided adhesiveness. These problems, of course, slow production, increase rejects, and increase overall costs.
As a result, the prior art discussed above still does not teach a flexible recording disc and related method of manufacture which are capable of the most cost and time efficient automated assembly.